Linux awk command

Question

Hello,

I am a beginner in using Linux, I have an input file with content like:

00.11.11.11.11.11
177.22.22.22

one line of Ethernet address and one line of IP address, how can I convert this file to:

IP: 177.22.22.22  MAC: 00.11.11.11.11.11

I think awk would do it, but I don't know how. Any ideas?

Thanks!

Answer 1

You can try it at ideone:

Really short!

{mac=$0;
 getline ip;
 print "IP: " ip  " MAC: " mac}

Answer 2

paste - - < input_file | awk '{print "IP: " $2 " MAC: " $1}'

Answer 3

{ if(mac) { print "IP:", $0, "MAC:", mac; mac = 0 } else mac = $0 }

Answer 4

awk -vRS= '{print "IP:", $2, "MAC:", $1;}'

which is equivalent to

awk 'BEGIN{RS="";}{print "IP:", $2, "MAC:", $1;}'

This works also with multiple input records:
"
00.11.22.33.44.55
123.45.67.89

11.22.33.44.55.66
11.22.33.99
"

->

"
IP: 123.45.67.89 MAC: 00.11.22.33.44.55
IP: 11.22.33.99 MAC: 11.22.33.44.55.66
"

Answer 5

Here's a sed version for variety:

sed 's/^/MAC: /;x;N;s/\n/IP: /;G;s/\n/  /' inputfile

If there is more than one pair of lines in the file:

sed 's/^/MAC: /;x;s/.*//;N;s/\n/IP: /;G;s/\n/  /' inputfile

Answer 6

awk -F"." 'NF>4{m=$0}NF==4{print "IP:"$0" MAC:"m}' file